Abstract: The relationship between partisan political affiliation and cognitive complexity was examined. It should be noted that cognitive complexity is only loosely correlated with intelligence and for the purposes of this study they should be considered entirely separate constructs. Participants (n = 2109) were students in an Introductory Psychology course at a large southeastern university participating for course credit. Using the Computer-Administered Rep Test (CART) to measure cognitive complexity and the newly designed Political Partisanship Scale to measure political partisanship in an online survey levels of cognitive complexity and political partisanship were measured. It was found that cognitive complexity does have a significant effect on political partisanship. Participants that were found to be more partisan on the Political Partisanship Scale were also found to be less cognitively complex and participants what had more moderate responses on the Political Partisanship Scale were found to be more cognitively complex.